Learn how to say Mementos correctly in English with this tutorial pronunciation video.
Oxford dictionary definition of the word memento:
Word forms: plural meˈmentos, meˈmentoes
([M-], Roman Catholic Church) either of two prayers in the Canon of the Mass, one for the living and one for the dead, beginning “Memento”
anything serving as a reminder or warning
L, imper. of meminisse, to remember: for IE base see mind